Many home centers and other retailers of window covering products purchase venetian blinds in stock sizes from a blind manufacturer and display those blinds in retail store locations. These retailers have machines, called cut-down machines, which a salesperson or technician can use to trim a stock blind to fit a window, door or other opening having dimensions smaller than the dimensions of a stock blind. Typically, the customer provides these dimensions. For example, a customer may tell a salesperson that the dimensions of the window to be covered by the blind are 34 inches wide and 48 inches tall. The stock blind closest to those dimensions is 36 inches wide and 48 inches in length. Consequently, it will be necessary to cut two inches from the width of the stock blind to create a blind that will fit the customer's window. Because the customer usually wants each of the two ladders in a venetian blind of this size to be the same distance from the edge of the blind nearest the ladder, the retailer will cut away an equal amount of material from each edge of the blind rather than cut all the material from one edge of the blind. In the example, one inch would be cut from each edge of the blind. If the blind is too long for the opening, extra slats or other window covering material can be removed from the bottom of the blind. A cut-down machine is not used for this purpose.
There are several types of blind trimming machines known in the art. One type of machine, disclosed in U.S. Pat. No. 6,615,698 to Chuang et al., has a pair of trimming units, which are adapted from conventional power miter saws. The blind to be cut down is placed upon a work surface so that each side of the blind is fitted through a trimming unit similar to a miter box. An adjustable end stop is provided near each trimming unit to enable the blind to be positioned in the trimming unit so that the correct amount of material is trimmed from the blind.
Another type of blind cutting machine has a cutting mechanism that can cut only one end of a blind. In this type of machine the operator uses the same cutting mechanism to cut one end or side of the blind then repositions the blind and cuts the opposite end of the blind. Most of these machines have a set of cutting dies that act as the cutting mechanism. The dies are typically arranged along a horizontal axis. There is one die for the headrail, one die for the bottom rail and an opening for the slats or other window covering material. The headrail and bottom rail are inserted into their respective dies and the slats are positioned in the openings. A blade or blades then moves across and opening to cut away material from the headrail, slats and bottom rail. Usually, the blades move together along a horizontal axis.
One shortcoming of the cut down machines known in the art, which do not use a saw, is that none of these machines permit the user to trim the ends of a venetian blind without moving the headrail, bottom rail and slats further apart from one another than they are when packaged.